The present invention relates to a method of recovering transactions made with smart cards. More in particular, the present invention relates to a method of completing interrupted smart card payments and revaluations. The present invention further relates to a smart card allowing interrupted transactions to be completed.
In existing smart card transactions, such as payments, an exchange of data takes place between a terminal (such as an electronic cash register equipped with a smart card reader) and a smart card (also called IC card). It can happen that an interruption of the payment takes place before this exchange of data is completed. Such an interruption may e.g. be caused by a power failure, or by a premature withdrawal of the card from the card reader. The result of such an interruption may cause a loss of data, which in turn may cause a loss of money.
European Patent Application EP 0 637 004, which is herewith incorporated by reference in this text, discloses a method of exchanging data between a smart card and a terminal. In this Prior Art method, it is ensured that the (security module of the) terminal is not credited before the smart card is debited. However, if the communication between the card and the terminal is interrupted after the card is debited but before the terminal is credited, it remains uncertain whether the debiting of the card has actually taken place.
The Prior Art does therefore not provide a method of making payments in which interrupted payments can be continued.